ipcMessageReader.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- *//* ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is Mozilla IPC. * * The Initial Developer of the Original Code is * Netscape Communications Corporation. * Portions created by the Initial Developer are Copyright (C) 2003 * the Initial Developer. All Rights Reserved. * * Contributor(s): * Conrad Carlen <ccarlen@netscape.com> * * Alternatively, the contents of this file may be used under the terms of * either the GNU General Public License Version 2 or later (the "GPL"), or * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */#include "ipcMessageReader.h"#include <string.h>//*****************************************************************************// ipcMessageReader//*****************************************************************************
PRUint8 ipcMessageReader::GetInt8()
{
if (mBufPtr < mBufEnd)
return *mBufPtr++;
mError = PR_TRUE;
return 0;
}
// GetInt16 and GetInt32 go to pains to avoid unaligned memory accesses that// are larger than a byte. On some platforms, that causes a performance penalty.// On other platforms, Tru64 for instance, it's an error.
PRUint16 ipcMessageReader::GetInt16()
{
if (mBufPtr + sizeof(PRUint16) <= mBufEnd) {
PRUint8 temp[2] = { mBufPtr[0], mBufPtr[1] };
mBufPtr += sizeof(PRUint16);
return *(PRUint16*)temp;
}
mError = PR_TRUE;
return 0;
}
PRUint32 ipcMessageReader::GetInt32()
{
if (mBufPtr + sizeof(PRUint32) <= mBufEnd) {
PRUint8 temp[4] = { mBufPtr[0], mBufPtr[1], mBufPtr[2], mBufPtr[3] };
mBufPtr += sizeof(PRUint32);
return *(PRUint32*)temp;
}
mError = PR_TRUE;
return 0;
}
PRInt32 ipcMessageReader::GetBytes(void* destBuffer, PRInt32 n)
{
if (mBufPtr + n <= mBufEnd) {
memcpy(destBuffer, mBufPtr, n);
mBufPtr += n;
return n;
}
mError = PR_TRUE;
return 0;
}
PRBool ipcMessageReader::AdvancePtr(PRInt32 n)
{
const PRUint8 *newPtr = mBufPtr + n;
if (newPtr >= mBuf && newPtr <= mBufEnd) {
mBufPtr = newPtr;
return PR_TRUE;
}
mError = PR_TRUE;
return PR_FALSE;
}